The present invention relates to a baler for forming cylindrical bales.
Many different designs of baler are currently available of the type for forming what are known as "big round bales" which are cylindrical having generally a diameter of the order of 4 to 6 feet and an axial length lying also in the range 4 to 6 feet. Bales of this type are generally used for forage crops and hence less attention has been given to losses of leaves, grain and chaff from the material since this is considered generally to be of less importance in forage type crops. However the amount of losses from a conventional baler are significantly high and under current economic conditions it is becoming more important to ensure that all crop materials are properly collected and baled.
The conventional baler includes simply a roller type pickup which is positioned immediately forwardly of the main baler housing and of a width substantially equal to the width of the main baler housing. The crop is therefore simply lifted from a windrow from the ground into the main baler housing where it is acted upon either by belts or by rollers to rotate the crop material about an axis transverse to the direction of movement so as to roll the crop material into the cylindrical shape bale.
The simple roller type pickup is very inefficient and has a significant loss in that much of the material is not properly picked up but left merely in the ground. Furthermore the action of the various belts and rollers upon the crop material tends to beat it vigorously which breaks away grain, leaves and chaff all of which are valuable but these simply fall through the openings between the belts and/or rollers and fall from the baler back to the ground.
Conventionally two type of balers are available of this sort. In the first type the bale is rotated by a belt arrangement which collapses to the diameter of the initial roll of material as it is rotated about the axis and then expands as the bale increases in diameter. This arrangement forms more solid bales that have constant density throughout the radius of the bale and thus are of maximum density for transportation. Another type of baler includes simply rollers at the periphery of the cylindrical chamber so that the material is rotated from the outside and this arrangement forms what are known as "soft-centre" bales. In both cases, however there are significant losses either between the belt sections or between the rollers.